Exam Professional Cloud Database Engineer topic 1 question 20 discussion

D. The question says backups and maintenance are an issue, so moving to a managed service (Cloud SQL) would be the right thing to do. That eliminates C and A. Option B could (depending upon the DB size) require a lot of downtime to export, copy the dump file to Cloud Storage, then import into Cloud SQL. Therefore, the least amount of downtime would be D. https://cloud.google.com/sql/docs/mysql/replication/configure-replication-from-external

The only issue that I have with the D answer is that an external replica is an explicit Cloud SQL concept not a MySQL concept; external replica is when you have a primary instance already in Cloud SQL, however, if you have your MySQL on premises then you are dealing with replication from an external server. I have read documentation for CloudSQL for MySQL before and I am more convinced with B to be frank

External replica is a setup with primary on cloud an the replica external to the cloud .eg.e on prem.. which is the reverse of what the question is looking for

This approach provides a seamless migration process with minimal impact on the application's availability.

Another good explanation from dynamic_dba.

I agree with D

D is the better option

minimal downtime!!! And the customer has read replicas + backups are expensive. D is the better option

D : External read replica will help achive minimal down time.

Correct answer is D: Create cloudsql replica of on-prem server and promote with almost-no downtime by pointing app to cloudsql. mysqldump is heavy and time-consuming operation (even though if you run it on on-prem read-replica, it will be identical to migrating to cloudsql using managed database migration service.

D create a read replica on cloud then promote it

B is correct answer

https://cloud.google.com/database-migration/docs/mysql/mysql-dump